Re: More than enough
The problem we face is not insecure operating systems with paranoid devs, otherwise Windows wouldn't be a thing, it's ignorant users not realising that clicking on an app you download from the Internet can go badly.
With that said, it is hard to tell between an app bundle with the mimetype/pdf icon and a name ending in .pdf, and an actual PDF. I don't know how helloSystem could fix this.